The present invention relates to compositions for surgical cement, based on at least one acrylic monomer and at least one acrylic polymer.
To obtain a surgical cement in the past, a solid phase, usually a powder consisting of polymethyl methacrylate, and a liquid syrup, consisting of a polymethyl methacrylate powder dissolved in methyl methacrylate, would be mixed and then hardened using a polymerization catalyst. The catalyst could be present in the polymethyl methacrylate powder constituting the solid phase. French Pat. No. 2,418,253, for example, describes a cement for bone surgery and stomatology, that is prepared with 35 to 70 weight percent solid acrylic polymer phase that contains a polymerization catalyst and from 30 to 65 weight percent viscous liquid phase, comprising from 15 to 35 weight percent acrylic polymer dissolved in at least 65 weight percent acrylic monomer. This cement, however, is highly exothermic when hardening, and is thus undesirable for use with sensitive tissues.
Furthermore, French Pat. No. 2,277,856 discloses a method for making a molding composition for the manufacture of dental prostheses by mixing 70 to 75 weight percent powder containing 60 to 90 weight percent polymethyl methacrylate and 10 to 40 weight percent poly-2-ethylhexyl acrylate, with 20 to 25 weight percent methyl methacrylate. Hardening takes place at 100.degree. C. in the presence of a polymerization catalyst. The patent also teaches the addition to the mixture of an exothermic peak suppressor, which is disclosed as being 0.01 weight percent, relative to the methyl methacrylate monomer, dipentene. This composition, however, takes too long to harden and is undesirable for use in circumstances where quick setting is desired.